================================================================== BUG: KCSAN: data-race in mb_mark_used / mb_update_avg_fragment_size write to 0xffff8881017f9b54 of 4 bytes by task 1787 on cpu 0: mb_mark_used+0x13b/0xc50 fs/ext4/mballoc.c:1942 ext4_mb_use_best_found+0x102/0x320 fs/ext4/mballoc.c:2014 ext4_mb_measure_extent fs/ext4/mballoc.c:2130 [inline] ext4_mb_complex_scan_group+0x349/0x850 fs/ext4/mballoc.c:2360 ext4_mb_regular_allocator+0x1a22/0x2520 fs/ext4/mballoc.c:2759 ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5514 ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4241 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638 ext4_getblk+0xb1/0x3d0 fs/ext4/inode.c:848 ext4_bread+0x28/0x130 fs/ext4/inode.c:900 ext4_append+0xd1/0x1c0 fs/ext4/namei.c:67 ext4_init_new_dir+0x177/0x500 fs/ext4/namei.c:2885 ext4_mkdir+0x329/0x760 fs/ext4/namei.c:2931 vfs_mkdir+0x2a4/0x370 fs/namei.c:3813 do_mkdirat+0x11d/0x200 fs/namei.c:3838 __do_sys_mkdir fs/namei.c:3856 [inline] __se_sys_mkdir fs/namei.c:3854 [inline] __x64_sys_mkdir+0x32/0x40 fs/namei.c:3854 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881017f9b54 of 4 bytes by task 21476 on cpu 1: ext4_mb_avg_fragment_size_cmp fs/ext4/mballoc.c:835 [inline] ext4_mb_rb_insert fs/ext4/mballoc.c:811 [inline] mb_update_avg_fragment_size+0x184/0x260 fs/ext4/mballoc.c:859 mb_mark_used+0xae0/0xc50 fs/ext4/mballoc.c:1993 ext4_mb_use_best_found+0x102/0x320 fs/ext4/mballoc.c:2014 ext4_mb_simple_scan_group+0x253/0x3a0 fs/ext4/mballoc.c:2292 ext4_mb_regular_allocator+0x1974/0x2520 fs/ext4/mballoc.c:2754 ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5514 ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4241 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638 ext4_iomap_alloc fs/ext4/inode.c:3426 [inline] ext4_iomap_begin+0x4a3/0x620 fs/ext4/inode.c:3476 iomap_apply+0x8d/0x400 fs/iomap/apply.c:46 __iomap_dio_rw+0x5af/0xad0 fs/iomap/direct-io.c:561 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xa04/0x11d0 fs/ext4/file.c:678 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000580e -> 0x0000580d Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 21476 Comm: syz-executor.2 Not tainted 5.13.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== syz-executor.2 (21476) used greatest stack depth: 9616 bytes left